On-body medical device securement

ABSTRACT

Devices and methods for maintaining a medical device on-body are provided. Embodiments include medical device securement systems having first and second on-body securement elements. Also provided are systems and kits for use maintaining a medical device on-body.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/118,441 filed May 29, 2011, now U.S. Pat. No. 8,734,344,which is a continuation of U.S. patent application Ser. No. 12/610,237filed Oct. 30, 2009, now U.S. Pat. No. 7,951,080, which is acontinuation of U.S. patent application Ser. No. 11/344,434 filed Jan.30, 2006, now U.S. Pat. No. 7,736,310, entitled “On-Body Medical DeviceSecurement”, the disclosures of each of which are incorporated herein byreference for all purposes.

BACKGROUND OF THE INVENTION

There are many instances in which it is necessary to maintain a medicaldevice “on-body”, i.e., secured to a body part of a patient, e.g., thearm, abdomen, or elsewhere. One such instance is maintaining a componentof an analyte monitoring system, e.g., a continuous analyte monitoringsystem, on the skin of a patient.

For example, monitoring of the level of glucose or other analytes, suchas lactate or oxygen or the like, in certain individuals is vitallyimportant to their health. The monitoring of glucose level isparticularly important to individuals with diabetes, as they mustdetermine when insulin is needed to reduce glucose levels in theirbodies or when additional sugar is needed to raise the level of glucosein their bodies. In this regard, devices and systems have been developedfor continuous or automatic monitoring of analytes, such as glucose, inthe blood stream or in interstitial fluid. Many of these analytemeasuring devices include a glucose sensor that is configured so that atleast a portion of the sensor is positioned below the epidermis, e.g.,in a blood vessel or in the subcutaneous tissue of a patient. The sensorcommunicates information about the glucose level to a componentpositioned above the skin, where in certain embodiments the component isintended to be maintained on the skin of the patient.

Despite techniques that have been developed to maintain analytemonitoring components and other medical devices on-body, the componentmay still become dislodged from its fixed position on the skin, e.g.,during vigorous exercise, or the by weakening of the adhesive attachingthe components on-body over time, and the like. This dislodgement may bea mere inconvenience, or may have severe consequences, e.g., if thedislodgement goes unnoticed for a substantial period of time duringwhich glucose information is prevented from being obtained. Furthermore,the mere possibility of dislodgement is a constant worry to the user.

As interest in maintaining medical devices, e.g., continuous analytemonitoring devices, in a fixed position on a skin surface continues,there is interest in devices and methods for attaching such device toskin.

SUMMARY OF THE INVENTION

Generally, the present invention relates to methods and devices formaintaining a medical device on-body. In certain embodiments, thepresent invention relates to the continuous and/or automatic in vivomonitoring of the level of an analyte using an analyte sensor and morespecifically, devices and methods for maintaining a component of acontinuous or automatic analyte sensing system adjacent a body part of apatient, where the analyte sensors include those in which at least aportion of the sensor is positioned partially beneath the epidermallayer of skin. The subject invention is further described with respectto analyte monitoring devices (also referred to herein as “sensors”,“analyte sensing devices”, and the like) and analyte monitoring systemsfor exemplary purposes only, where such description is in no wayintended to limit the scope of the invention. It is understood that thesubject invention is applicable to any medical device in which at leasta portion of the device is intended to be maintained in place on apatient.

Embodiments include devices and methods for maintaining medical devices,e.g., on-body analyte sensor control units, in place and include one ormore on-body securement elements. In certain embodiments, first andsecond on-body securement elements are employed, where the two elementsare used together to maintain a medical device such as an on-body sensorcontrol unit in place on a patient. First and second on-body securementelements may be used in a layered construction such that at least aportion of a medical device of interest is sandwiched between the twosecurement elements to hold the medical device on a body part.

One or both elements may include adhesive for attachment to skin and/orto the other element and/or the medical device (e.g., an on-skin sensorcontrol unit). In certain embodiments, an on-body securement elementincludes an adhesive area and a non adhesive area. The non adhesive areamay be an opening in the securement element, a pocket or other surfaceor the like that does not have adhesive. The area that does not includeadhesive may approximate the size and shape of at least a portion of themedical device to be maintained in place with the securement element sothat the non adhesive area may encompass the medical device. Inembodiments that include an opening, the opening is positionable aroundthe medical device so as not to completely cover it.

Embodiments include on-body securement elements that are easy to use,e.g., that are easy to position on a body part even in instances inwhich the area of the body part on which it is desired to position themedical device is not within the direct line of site of the individualperforming the positioning. In certain embodiments, a securement elementmay include one or more release liners adapted to facilitate ease ofuse, where in some embodiments a plurality of release liners areincluded and arranged for easy removal from, and positioning of, thesecurement element.

Also provided are systems and kits.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 shows a block diagram of an exemplary embodiment of an analytemonitor using an implantable analyte sensor, according to one embodimentof the invention;

FIG. 2 is a cross-sectional view of an embodiment of an on-skin sensorcontrol unit, according to one embodiment of the invention;

FIG. 3 is a top view of a base of the on-skin sensor control unit ofFIG. 2;

FIG. 4 is a bottom view of a cover of the on-skin sensor control unit ofFIG. 2;

FIG. 5A is a block diagram of an embodiment of an on-skin sensor controlunit, according to one embodiment of the invention;

FIG. 5B is a block diagram of an embodiment of an on-skin sensor controlunit, according to one embodiment of the invention;

FIG. 6 is a perspective view of the on-skin sensor control unit of FIG.2 on the skin of a patient;

FIG. 7A is a top view of one embodiment of an on-skin sensor controlunit, according to one embodiment of the invention;

FIG. 7B is a top view of one embodiment of a mounting unit of theon-skin sensor control unit of FIG. 7A;

FIG. 8A is a top view of another embodiment of an on-skin sensor controlunit and a sensor, according to one embodiment of the invention;

FIG. 8B is a top view of one embodiment of a mounting unit of theon-skin sensor control unit of FIG. 8A;

FIG. 8C is a top view of one embodiment of a housing for at least aportion of the electronics of the on-skin sensor control unit of FIG.8A;

FIG. 8D is a bottom view of the housing of FIG. 8C;

FIG. 9A is an exemplary embodiment of an on-body securement patchaccording to one embodiment of invention;

FIG. 9B is an exemplary embodiment of an on-body securement patch thatincludes a medical device placement area according to one embodiment ofthe invention;

FIG. 10A is an exemplary embodiment of an on-body securement bandaccording to one embodiment of the subject invention;

FIG. 10B is an exemplary embodiment of an on-body securement band thatincludes a medical device placement area, according to one embodiment ofthe subject invention;

FIG. 11 is an exemplary embodiment of an on-body securement band orcuff, according to one embodiment of the subject invention;

FIG. 12A is an exemplary embodiment of a release liner protective systemprotecting an adhesive containing a body securement element, accordingto one embodiment of the subject invention, and FIG. 12B shows theadhesive containing-securement element with release liner system thusremoved, positioned about an on-body control unit mount;

FIG. 13 is a top view of one embodiment of an analyte sensor, accordingto one embodiment of the invention;

FIG. 14A is a cross-sectional view of the analyte sensor of FIG. 13;

FIG. 14B is a cross-sectional view of another embodiment of an analytesensor, according to one embodiment of the invention;

FIG. 15A is a cross-sectional view of another embodiment of an analytesensor, according to one embodiment of the invention;

FIG. 15B is a cross-sectional view of a fourth embodiment of anotherembodiment of a sensor, according to one embodiment of the invention;

FIG. 16 is a cross-sectional view of another embodiment of an analytesensor, according to one embodiment of the invention;

FIG. 17 is an expanded top view of a tip-portion of the analyte sensorof FIG. 16;

FIG. 18 is an expanded bottom view of a tip-portion of the analytesensor of FIG. 16;

FIG. 19 is a side view of the analyte sensor of FIG. 13; and

FIG. 20 is a block diagram of one embodiment of a receiver/display unit,according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Before the present invention is described, it is to be understood thatthis invention is not limited to particular embodiments described, assuch may, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, since the scope ofthe present invention will be limited only by the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the invention. The upper and lowerlimits of these smaller ranges may independently be included in thesmaller ranges as also encompassed within the invention, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, the preferredmethods and materials are now described.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise.

“May” refers to optionally, and when two or more items (for example,elements or processes) are referenced by an alternative “or”, thisindicates that either could be present separately or any combination ofthem could be present together except where the presence of onenecessarily excludes the other or others.

Any recited method can be carried out in the order of events recited orin any other order which is logically possible. Reference to a singularitem, includes the possibility that there are plural of the same itempresent.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinvention.

The figures shown herein are not necessarily drawn to scale, with somecomponents and features being exaggerated for clarity.

As summarized above, the present invention is related to devices andmethods for maintaining a medical device in place on the body of apatient. The invention is primarily described herein with respect tomaintaining an analyte sensing device and more particularly an on-bodyanalyte control unit adapted for use with an analyte sensor in place ona patient for exemplary purposes only, where such description is in noway intended to limit the scope of the invention. It is to be understoodthat the invention may be used with a variety of medical devicesintended to be maintained in place on a patient. For example, thesubject invention may be used to secure an infusion set, e.g., of aninsulin pump or the like, in place on the body of a patient.

The present invention is applicable to any analyte monitoring systemsuch as those using a sensor wherein at least a portion of the sensor ispositionable beneath the skin of the user for the in vivo determinationof a concentration of an analyte, such as glucose, lactate, and thelike, in a body fluid. Additional analytes that may be determinedinclude but are not limited to, for example, acetyl choline, amylase,bilirubin, cholesterol, chorionic gonadotropin, creatine kinase (e.g.,CK-MB), creatine, DNA, fructosamine, glucose, glutamine, growthhormones, hormones, ketones, lactate, peroxide, prostate-specificantigen, prothrombin, RNA, thyroid stimulating hormone, and troponin.The concentration of drugs, such as, for example, antibiotics (e.g.,gentamicin, vancomycin, and the like), digitoxin, digoxin, drugs ofabuse, theophylline, and warfarin, may also be determined.

A sensor may be, for example, subcutaneously positionable in a patientfor the continuous or periodic monitoring of an analyte in a patient'sinterstitial fluid. This may be used to infer the glucose level in thepatient's bloodstream. The sensors also include in vivo analyte sensorsinsertable into a vein, artery, or other portion of the body containingfluid. These sensors may be configured for monitoring the level of theanalyte over a time period which may range from minutes, hours, days,weeks, or longer. Of interest are analyte sensors, such as glucosesensors, that are capable of providing analyte data for about one houror more, e.g., about a few hours or more, e.g., about a few days ofmore, e.g., about three or more days, e.g., about five days or more,e.g., about seven days or more, e.g., about several weeks or months.

Analyte monitoring systems generally include, at a minimum, an analytesensor and a control unit, where in many embodiments the control unit isintended to be held in place on a body part of the patient. In certainembodiments, a system may only include a sensor and control unit. Theseanalyte monitoring systems may be utilized under a variety ofconditions. The particular configuration of a sensor and other unitsused in an analyte monitoring system may depend on the use for which thesensor and system are intended and the conditions under which the sensorand system will operate. As noted above, embodiments include a sensorconfigured for positioning into the body of a patient or user. The term“positioning” is meant broadly to include wholly implantable sensors andsensors in which only a portion of which is positioned under the skinand a portion of which resides above the skin, e.g., for contact to atransmitter, receiver, transceiver, processor, etc.

For example, positioning of a sensor may be made in the arterial orvenous systems for direct testing of analyte levels in blood.Alternatively, a sensor may be positioned in the interstitial tissue fordetermining the analyte level in interstitial fluid. This level may becorrelated and/or converted to analyte levels in blood or other fluids.Sensors may also be positioned in other regions of the body to determineanalyte levels in other fluids. Examples of suitable sensors for use inthe analyte monitoring systems of the invention are described herein andin, for example, U.S. Pat. Nos. 6,134,461, 6,175,752, and elsewhere.

FIG. 1 illustrates in block diagram form, an exemplary embodiment of ananalyte monitoring system 40. Analyte monitoring system 40 includes, atminimum, a sensor 42, at least a portion of the sensor which isconfigured for positioning (e.g., subcutaneous, venous, or arterialpositioning) into a patient, and a sensor control unit 44. Sensor 42 iscoupleable to sensor control unit 44 which, as noted above, is intendedto be worn by the patient. Sensor control unit 44 operates sensor 42,including, for example, providing a voltage across the electrodes of thesensor and collecting signals from the sensor. In certain embodiments,the control unit is shaped and sized to be concealable. For example, incertain embodiments, on-skin sensor control unit 44 has a thin, ovalshape to enhance concealment, as illustrated in FIGS. 3 and 4. However,other shapes and sizes may be used. On-skin sensor control unit 44includes a housing 45, as illustrated in FIGS. 2-4 for example.

Sensor control unit 44 may evaluate the signals from sensor 42 and/ortransmit the signals to one or more optional receiver/display units 46,48 for evaluation. Sensor control unit 44 and/or receiver/display units46, 48 may display or otherwise communicate the current level of theanalyte. Furthermore, sensor control unit 44 and/or receiver/displayunits 46, 48 may indicate to the patient, via, for example, an audible,visual, or other sensory-stimulating alarm, when the level of theanalyte is at or near a threshold level. In some embodiments, anelectrical shock may be delivered to the patient as a warning throughone of the electrodes or the optional temperature probe of the sensor.For example, if glucose is monitored then an alarm may be used to alertthe patient to a hypoglycemic or hyperglycemic glucose level and/or toimpending hypoglycemia or hyperglycemia.

Sensor 42 and the electronic components within on-skin sensor controlunit 44 are coupled via conductive contacts 80. The one or more workingelectrodes 58, counter electrode 60 (or counter/reference electrode),optional reference electrode 62, and optional temperature probe 66 (seefor example FIGS. 13-17) are attached to individual conductive contacts80. In some embodiments, the conductive contacts are provided on theexterior of the housing (see for example FIGS. 7A and 7B) and in otherembodiments the conductive contacts are provided on the interior of thehousing, e.g., within a hollow or recessed region. In the illustratedembodiment of FIGS. 2-4, the conductive contacts 80 are provided on theinterior of the on-skin sensor control unit 44.

The on-skin sensor control unit may include at least a portion of theelectronic components that operate the sensor and the analyte monitoringdevice system. One embodiment of the electronics in the on-skin controlunit 44 is illustrated as a block diagram in FIG. 5A. The electroniccomponents of on-skin sensor control unit 44 may include a power supply95 for operating the on-skin control unit and the sensor, a sensorcircuit 97 for obtaining signals from and operating the sensor, ameasurement circuit 96 that converts sensor signals to a desired format,and a processing circuit 109 that, at minimum, obtains signals from thesensor circuit 97 and/or measurement circuit 96 and provides the signalsto an optional transmitter 98. In some embodiments, processing circuit109 may also partially or completely evaluate the signals from thesensor and convey the resulting data to the optional transmitter 98and/or activate an optional alarm system 94 (see FIG. 5B) if the analytelevel exceeds a threshold. Processing circuit 109 often includes digitallogic circuitry.

On-skin sensor control unit 44 may optionally contain a transmitter ortransceiver 98 for transmitting the sensor signals or processed datafrom processing circuit 109 to a receiver (or transceiver)/display unit46, 48; a data storage unit 102 for temporarily or permanently storingdata from processing circuit 109; a temperature probe circuit 99 forreceiving signals from and operating a temperature probe 66; a referencevoltage generator 101 for providing a reference voltage for comparisonwith sensor-generated signals; and/or a watchdog circuit 103 thatmonitors the operation of the electronic components in the on-skinsensor control unit. Moreover, sensor control unit 44 may include a biascurrent generator 105 to correctly bias analog and digital semiconductordevices, an oscillator 107 to provide a clock signal, and a digitallogic and timing component to provide timing signals and logicoperations for the digital components of the circuit.

FIG. 5B illustrates a block diagram of another exemplary on-skin sensorcontrol unit 44 that also includes optional components such as areceiver (or transceiver) 110 to receive, for example, calibration data;a calibration storage unit (not shown) to hold, for example, factory-setcalibration data, calibration data obtained via the receiver 110 and/oroperational signals received, for example, from a receiver/display unit46, 48 or other external device; an alarm system 94 for warning thepatient; and a deactivation switch 111 to turn off the alarm system.

The electronics in the on-skin sensor control unit 44 and the sensor 42may be operated using a power supply 95. Sensor control unit 44 may alsooptionally include a temperature probe circuit 99. The output fromsensor circuit 97 and optional temperature probe circuit is coupled intoa measurement circuit 96 that obtains signals from sensor circuit 97 andoptional temperature probe circuit 99 and, at least in some embodiments,provides output data in a form that, for example can be read by digitalcircuits.

In some embodiments, the data from processing circuit 109 is analyzedand directed to an alarm system 94 (see FIG. 5B) to warn the user. Forexample, an alarm may notify a patient of a hypo- or hyperglycemicevent.

In some embodiments, the data (e.g., a current signal, a convertedvoltage or frequency signal, or fully or partially analyzed data) fromprocessing circuit 109 is transmitted to one or more receiver/displayunits 46, 48 using a transmitter 98 in on-skin sensor control unit 44.The transmitter has an antenna 93, such as a wire or similar conductor,formed in housing 45.

In addition to a transmitter 98, an optional receiver 110 may beincluded in the on-skin sensor control unit 44. In some cases,transmitter 98 is a transceiver, operating as both a transmitter and areceiver. Receiver 110 (and/or receiver display/units 46, 48) may beused to receive calibration data for the sensor 42. The calibration datamay be used by processing circuit 109 to correct signals from sensor 42.This calibration data may be transmitted by receiver/display unit 46, 48or from some other source such as a control unit in a doctor's office.The on-skin sensor control unit 44 may include an optional data storageunit 102 which may be used to hold data (e.g., measurements from thesensor or processed data).

In certain embodiments, on-skin sensor control unit 44 includes a sensorport through which a sensor enters the subcutaneous tissue of thepatient. A sensor may be inserted into the subcutaneous tissue of thepatient through the sensor port. The on-skin sensor control unit maythen be placed on the skin of the patient with a sensor being threadedthrough the sensor port. If the housing of the sensor has, for example,a base and a cover, then the cover may be removed to allow the patientto guide the sensor into the proper position for contact with conductivecontacts 80. Alternatively, if the conductive contacts are within thehousing the patient may slide the sensor into the housing until contactis made between the contact pads of the sensor and the conductivecontacts. The sensor control unit may have a structure which obstructsthe sliding of the sensor further into the housing once the sensor isproperly positioned with the contact pads in contact with the conductivecontacts. In other embodiments, the conductive contacts are on theexterior of the housing. In these embodiments, the patient guides thecontacts pads of the sensor into contact with the conductive contacts ofthe control unit. In some cases, a guiding structure may be provided onthe housing which guides the sensor into the proper position. An exampleof such a structure includes a set of guiding rails extending from thehousing and having the shape of the sensor.

One or more receiver/display units 46, 48 may be provided with theanalyte monitoring device 40 for easy access to the data generated bythe sensor 42 and may, in some embodiments, process the signals from theon-skin sensor control unit 44 to determine the concentration or levelof analyte in the subcutaneous tissue. The receiver may be atransceiver. Receivers may be palm-sized and/or may be adapted to fit ona belt or within a bag or purse that the patient carries.

The receiver/display units 46, 48, as illustrated in block form at FIG.20, typically include a receiver 150 to receive data from the on-skinsensor control unit 44, an analyzer 152 to evaluate the data, a display154 to provide information to the patient, and an alarm system 156 towarn the patient when a condition arises. The receiver/display units 46,48 may also optionally include a data storage device 158, a transmitter160, and/or an input device 162. Data received by the receiver 150 maythen be sent to an analyzer 152.

The output from the analyzer 152 may be provided to a display 154. Thereceiver/display units 46, 48 may also include a number of optionalitems such as a data storage unit 158 to store data, a transmitter 160which can be used to transmit data, and an input device 162, such as akeypad or keyboard.

In certain embodiments, the receiver/display unit 46, 48 is integratedwith a calibration unit (not shown). For example, the receiver/displayunit 46, 48 may, for example, include a conventional blood glucosemonitor. Devices may be used including those that operate using, forexample, electrochemical and colorimetric blood glucose assays, assaysof interstitial or dermal fluid, and/or non-invasive optical assays.When a calibration of the implanted sensor is needed, the patient usesthe integrated in vitro monitor to generate a reading. The reading maythen, for example, automatically be sent by the transmitter 160 of thereceiver/display unit 46, 48 to calibrate the sensor 42.

In certain embodiments, analyte data (processed or not) may becommunicated, e.g., forwarded (such as by communication) to a remotelocation such as a doctor's office if desired, and received there forfurther use (such as further processing).

As described, on-skin sensor control unit 44 is intended to be worn“on-body” by the patient, e.g., attached directly or indirectly to theskin 75 of the patient, as illustrated for example in FIG. 6. Thesubject invention provides methods and devices for such on-bodyplacement and securement. As described in greater detail below, certainembodiments include only one on-body securement element and certainembodiments include at least a first on-body securement element and asecond on-body securement element. A first securement element may beadapted for attachment to a skin surface, e.g., may be anadhesive-containing element or the like, and also to on-skin controlunit. For example, a first side may include adhesive for attachment toskin and a second side may be adapted for mating with a control unit. Asecond securement element may be adapted to be positionable over atleast a portion of the first element, including a first element/controlunit structure. In some embodiments, only one on-body securementelements may be used or one may be used in certain instances and theother or both may be used in certain other instances. For example, afirst element may be used for everyday use, and the second element maybe included and used with the first (or used alone) in certaininstances, e.g., vigorous activities such as exercising and the like.

Referring again to FIG. 6, on-skin sensor control unit 44 may beattached by adhering the on-skin sensor control unit 44 directly to theskin 75 of the patient with an adhesive provided on at least a portionof the housing 45 of the on-skin sensor control unit 44 which contactsthe skin 75 or by suturing the on-skin sensor control unit 44 to theskin 75 through suture openings (not shown) in the sensor control unit44.

In other embodiments, a mounting unit 77 is employed to attach thehousing 45 of the on-skin sensor control unit 44 to the skin 75.Mounting unit 77 may be part of the on-skin sensor control unit 44 ormay be separate. One example of a suitable mounting unit is adouble-sided adhesive strip, one side of which is adhered to a surfaceof the skin of the patient and the other side is adhered to the on-skinsensor control unit 44. In this embodiment, the mounting unit 77 mayhave an optional opening 79 which is large enough to allow insertion ofsensor 42 through opening 79 for electrical contact with the controlunit. Alternatively, the sensor may be inserted through a thin adhesiveand into the skin.

A variety of adhesives may be used to adhere the on-skin sensor controlunit 44 to the skin 75 of the patient, either directly or using themounting unit 77, including, for example, pressure sensitive adhesives(PSA) or contact adhesives. An adhesive is usually chosen which is notirritating to all or a majority of patients for at least the period oftime that a particular sensor 42 is implanted in the patient, e.g., maybe hypoallergenic adhesive. Alternatively, a second adhesive or otherskin-protecting compound may be included with the mounting unit so thata patient, whose skin is irritated by the adhesive on the mounting unit77, may cover his skin with the second adhesive or other skin-protectingcompound and then place the mounting unit 77 over the second adhesive orother skin-protecting compound. This should substantially prevent theirritation of the skin of the patient because the adhesive on themounting unit 77 is no longer in contact with the skin, but is insteadin contact with the second adhesive or other skin-protecting compound.Adhesives that may be used includes, but is not limited to acrylicadhesives, and the like, e.g., a polyurethane membrane coated with alayer of an acrylic adhesive such as TEGADERM from 3M Corporation.

Another embodiment of a mounting unit 77 that may be used in an on-skinsensor control unit 44 is illustrated in FIGS. 7A and 7B. Mounting unit77 and housing 45 of on-skin sensor control unit 44 are mounted togetherin, for example, an interlocking manner, as shown in FIG. 7A. Mountingunit 77 is formed, for example, using plastic or polymer materials,including, for example, polycarbonate, polyvinyl chloride, polyethylene,polypropylene, polystyrene, ABS polymers, and copolymers thereof. Themounting unit 77 may be formed using a variety of techniques including,for example, injection molding, compression molding, casting, and othermolding methods.

The mounting unit 77 may include an adhesive on a bottom surface toadhere to the skin of the patient or mounting unit 77 used inconjunction with, for example, double-sided adhesive tape or the like.The mounting unit 77 may include an opening 79 through which the sensor42 is inserted, as shown for example in FIG. 7B. Mounting unit 77 mayalso include a support structure 220 for holding a sensor in place andagainst the conductive contacts 80 of the on-skin sensor control unit.Mounting unit 77, also, optionally, includes a positioning structure222, such as an extension of material from the mounting unit, thatcorresponds to a structure (not shown), such as an opening, on a sensor42 to facilitate proper positioning of the sensor, for example, byaligning the two complementary structures.

In another embodiment, a coupled mounting unit 77 and housing 45 of anon-skin sensor control unit 44 is provided on an adhesive patch 204 withan optional cover 206 to protect and/or confine housing 45 of theon-skin sensor control unit 44, as illustrated in FIG. 8A. The optionalcover may contain an adhesive or other mechanism for attachment to thehousing 45 and/or mounting unit 77. Mounting unit 77 typically includesan opening 49 through which a sensor 42 is disposed, as shown in FIG.8B. Opening 49 may optionally be configured to allow insertion of thesensor 42 through the opening using an insertion device or insertiongun. Housing 45 of on-skin sensor control unit 44 has a base 74 and acover 76, as illustrated in FIG. 8C. A bottom view of housing 45, asshown in FIG. 8D, illustrates ports 230 through which conductivecontacts (not shown) extend to connect with contact pads on the sensor42. A board (not shown) for attachment of circuit components mayoptionally be provided within on-skin sensor control unit 44.

In some embodiments, the adhesive on an on-skin sensor control unit 44and/or on any of the embodiments of mounting unit 77 is water resistantor waterproof to permit activities such as showering and/or bathingwhile maintaining adherence of the on-skin sensor control unit to theskin of the patient and, at least in some embodiments, preventing waterfrom penetrating into the sensor control unit. The use of a waterresistant or waterproof adhesive combined with a water resistant orwaterproof housing 45 protects the components in sensor control unit 44and the contact between conductive contacts 80 and sensor 42 from damageor corrosion. An example of a non-irritating adhesive that repels wateris TEGADERM.

As described above, in certain embodiments an on-body securement elementmay be adapted to be positionable about at least a portion of thecontrol unit and may be used in addition to, or instead of, anysecurement element described herein. For example, a first on-bodysecurement element may be used that is attachable to a body part, e.g.,includes an adhesive for attachment to the skin. The adhesive may bedirectly on the control unit or may be a separate component, e.g., amounting unit or an adhesive patch to which a mounting unit/control unitis attachable, etc. The on-body securement element, if it includesadhesive, may be adapted to adhesively attach to the skin and/or mountand/or control unit, and/or a first adhesive patch positioned adjacentthe skin and upon which the mount and/or control unit resides, e.g., incertain embodiments with a control unit held therebetween.

A second securement element may be included and may be a securementpatch or band and may or may not include adhesive. FIGS. 9-11 showexemplary embodiments of on-body securement elements. Securementelements 300 and 310 of FIGS. 9A and 9B, respectively, are in the formof securement patches, e.g., adhesive patches. The adhesive patches mayinclude adhesive on a backing layer. Securement elements 400 and 410 ofFIGS. 10A and 10B, respectively, are in the form of securement bands andembodiment 500 of FIG. 11 is in the form of a securement strap or cuff.Elements 300 and 400 of FIGS. 9A and 10A, respectively, aresubstantially the same as elements 310 and 410 of FIGS. 9B and 10B,respectively, except the embodiments of FIGS. 9A and 10A do not includea control unit area 315 and 415, respectively (it is understood thatembodiment 500 of FIG. 11 may also include a control unit area (notshown)), which may include one or more of: a hole, a covering such as atransparent shield (e.g., non-adhesive), a recess or pouch, or isotherwise a non adhesive area. In those embodiments in which controlunit area 315 is an opening in the securement element, the openingprovides an area through which a control unit may be positioned so thatthe control unit is not completely covered by the on-body securementelement. In certain embodiments, the securement element may be opaqueexcept for an opening covered with a transparent shield, the shieldconfigured to be positioned over a control unit. The shield may becompressible to allow a user to actuate buttons, knobs, thumbwheels,etc., if provided on the control unit and which may be positionedbeneath the shield.

A non adhesive-including area may be particularly relevant if an on-bodysecurement element includes an adhesive-including area. An opening (orotherwise non-adhesive surface) provides an adhesive-free area whichprevents accumulation of adhesive residue on the control unit surface,improving moisture transmission rates and eliminating entrapped pocketsthat may serve as potential sites for water accumulation. An opening orrecess provides a further advantage of providing an easily identifiablereference point for registering the securement element with a controlunit so that it may be correctly and easily positioned about the controlunit even in instances in which the control unit is not within thedirect line of site of the patient. This may be particularly importantfor patients with diminished hand-eye coordination and/or manualdexterity and/or visual capabilities.

In certain embodiments, an on-body securement element provides mildcompression of a body part so that the element does not readily slip offof the patient. The on-body securement element may be further tightenedusing a fastening strap or other mechanism which cinches the elementtighter onto the arm.

In embodiments in which the on-body securement element is a patch, e.g.,an adhesive-including patch, as shown for example in FIGS. 9A and 9B,securement patches 300 and 310 include support 312. Certain embodimentsmay include adhesive. For example, a first on-body securement element inthe form of a first adhesive patch attachable to the skin may beemployed. The first patch may be adapted for retaining a mounting unitand/or control unit and may be sized to include an extended edge so thatonce a mount and/or control unit is positioned thereupon, a perimeteredge is available for attachment to a second adhesive patch.Accordingly, a second adhesive patch is positioned either completelyover the control unit, e.g., in the case of the embodiments of FIG. 9A,or positioned around the control unit rather than over it (butpositioned about the mounting unit or adhesive patch carrying a mountingunit)—using the extended edge of the first adhesive patch as a point ofattachment between the first and second patches.

Other securement embodiments may be in the form of an arm band or strapthat partially or completely encircle a body part such as an arm, leg,wrist, abdomen, etc., as shown for example in FIGS. 10A, 10B and 11.Analogous to a patch securement element, an arm band or strapsecurement, if inclusive of adhesive, may be adapted to adhesivelyattach to the skin and/or mount and/or control unit, and/or a firstadhesive patch positioned adjacent the skin and upon which the mountand/or control unit resides.

In certain embodiments, an on-body securement element may be a tubularstructure such as securement bands 400 and 410 having supports 412, asshown in FIGS. 10A and 10B, e.g., elasticized tubular elements. Incertain embodiments, a securement element may be in the form of a strapor cuff such as securement element 500 having support 512, as shown inFIG. 11. Securement element 500 may include joinable ends 502 and 504for forming a tubular structure. Opposing ends 502 and 504 may includefasteners 510 to connect the opposing ends together to form a tubularstructure and surround a body part of a patient. Fasteners that may beused include but are not limited to snaps, buttons, zippers,hook-and-loop fastener, laces, Velcro®, latches, etc. The fasteningsystem may bring the opposing ends of a securement element in proximityto permit coaptation.

In addition to the support layer and adhesive layer (if present),additional layers may be included. For example, a removable layer may bepositioned adjacent to one or more surfaces (e.g., adjacent an adhesivelayer surface and/or casting layer surface) of a securement element forprotection of the securement element from the environment. For example,a securement element having an adhesive surface may include a peelablerelease liner adjacent the adhesive surface to maintain the integrity ofthe adhesive until use and/or a casting layer. In certain embodiments, asecurement element may be in the form of a sandwich configuration suchas a laminate or the like. A securement element may include adhesivedisposed on a backing, the adhesive/backing structure may be sandwichedbetween two removable layers: a removable release liner adjacent theadhesive and a removable casting layer adjacent the backing. Thematerials thereof may be any suitable materials, including materialsdescribed herein and others. Any suitable materials may be used, wherein certain embodiments a release liner is a polyester such as PET or PP,and the like, or siliconized paper (e.g., siliconized Kraft paper), orthe like, an adhesive is polyacrylate, silicone, PIB, natural orsynthetic rubber or the like, a backing is a polyurethane film, or thelike, in the form of films, foams, nonwovens, etc., and the castinglayer is PE, or the like.

In certain embodiments, the removable layer(s) may have greater rigiditythan the securement element with which it is employed. This relativerigidity may provide structural stability and facilitate peeling-away ofthe layer from the securement element by the patient. A removable layersuch as a release liner may include tabs or the like graspable by apatient.

In certain embodiments, a plurality of release liners is used. Aplurality of release liners may increase the ease of removal of therelease liners from the securement element and the ease of use of thesecurement element by providing one-handed, self-application of asecurement element.

An embodiment of a release liner system 600 having a plurality ofrelease liners 604 a, 604 b, 604 c, and 604 d is shown in FIGS. 12A and12B. FIG. 12A shows a release liner protective system 600 protecting asurface an adhesive surface 310 b of securement element 310, e.g.,adhesive 310 b may be present on backing layer 310 a, according to thesubject invention. Front and back faces are shown in FIG. 12B, right andleft figures respectively. Accordingly, left FIG. 12B shows securementelement 310 with release liner system 600 thus removed and positionedabout mounting unit 77, and more specifically the adhesive of securementelement 310 is adhered to an adhesive patch (not shown) that retainmounting unit 77. Mounting unit 77 is positioned within control unitarea 315.

Release liner system 600 may be used with any securement element, hereinshown in FIGS. 12A and 12B as used with element 310 of FIG. 9B forexemplary purposes. Removable system 600 of peelable release layers 604are adjacent one (adhesive) side 310 b of element 310 and removablelayer 602 is adjacent a second, opposite (backing) side 310 a. Side 310b includes a plurality of release liners 604 a, 604 b, 604 c and 604 d,wherein more or less may be used.

In use, an on-body control unit may be first attached to a body part ofa patient, e.g., using a first securement element in the form of anadhesive patch which, at one side, is attached to a body part and at asecond side is attached to a mounting unit and control unit. To securethe control unit in place, a patient may hold second securement element310 carrying release liner system 600 with one hand, e.g., with a righthand to apply to the left arm, and vice versa. A first release liner(e.g., release liner 604 a) may be peeled away from securement element310, e.g., using a tab or the like, and securement element 310, with theother release liners still in contact therewith, may be positioned aboutthe control unit so that the hole of the securement element/releaseliner system is positioned around the control unit. Once positioned overthe control unit, remaining release liners 604 b, 604 c . . . may beeasily removed from securement element 310. Removable layer 602, ifpresent, may be removed at any convenient time, e.g., before or afterremoval of release liner 604.

First and/or second on-body securement elements may be made from anysuitable material where in many embodiments the material is selected forprolonged contact with skin with minimal skin irritation, as notedabove. The material may be conformable to a patient's body part.Materials include but are not limited to those described herein andpolyurethane; polyolefin, such as polyethylene and polypropylene;polyvinylchloride; ethylene vinyl acetate; woven fabrics; nonwovenfabrics; and the like, and may be perforated or nonperforated. Incertain embodiments, the material may be perspiration-absorbingmaterial. For example, elements may include a backing with an adhesivelayer thereon. The backing may be fabricated from one or more of thesematerials.

As described, the subject invention, in accordance with variousembodiments, may be used to secure any medical device to a body part andhas been described primarily with reference to securing on-body analytesensor control units to a body part. In such embodiments, any suitableanalyte sensor may be employed, where exemplary analyte sensors are nowdescribed, where such description is in no way intended to limit thescope of the invention as it will be apparent that the subject inventionis applicable to any analyte sensor and sensor system.

FIG. 13 shows an exemplary embodiment of an analyte sensor 42. Sensor 42includes at least one working electrode 58 and a substrate 50. Thesensor 42 may also include at least one counter electrode 60 (orcounter/reference electrode) and/or at least one reference electrode 62(see for example FIG. 18). The counter electrode 60 and/or referenceelectrode 62 may be formed on the substrate 50 or may be separate units.For example, the counter electrode and/or reference electrode may beformed on a second substrate which is also implantable in the patientor, for some embodiments of the sensors, the counter electrode and/orreference electrode may be placed on the skin of the patient with theworking electrode or electrodes being implanted into the patient. Theuse of an on-the-skin counter and/or reference electrode with animplantable working electrode is described in, e.g., U.S. Pat. No.5,593,852.

The working electrode or electrodes 58 are formed using conductivematerials 52. The counter electrode 60 and/or reference electrode 62, aswell as other optional portions of the sensor 42, such as a temperatureprobe 66 (see for example FIG. 18), may also be formed using conductivematerial 52. The conductive material 52 may be formed over a smoothsurface of the substrate 50 or within channels 54 (see FIG. 14A) formedby, for example, embossing, indenting or otherwise creating a depressionin the substrate 50.

A sensing layer 64 (see for example FIGS. 14A and 14B) may be providedproximate to or on at least one of the working electrodes 58 tofacilitate the electrochemical detection of the analyte and thedetermination of its level in the sample fluid, particularly if theanalyte cannot be electrolyzed at a desired rate and/or with a desiredspecificity on a bare electrode.

In addition to the electrodes 58, 60, 62 and the sensing layer 64, thesensor 42 may also include optional components such as one or more ofthe following: a temperature probe 66 (see for example FIGS. 16 and 18),a mass transport limiting layer 74, e.g., a matrix such as a membrane orthe like, (see for example FIG. 19), a biocompatible layer 75 (see forexample FIG. 19), and/or other optional components, as described below.Each of these optional items enhances the functioning of and/or resultsfrom sensor 42, as discussed below.

The substrate 50 may be formed using a variety of non-conductingmaterials, including, for example, polymeric or plastic materials andceramic materials. Suitable materials for a particular sensor may bedetermined, at least in part, based on the desired use of the sensor andproperties of the materials.

In addition to considerations regarding flexibility, it is oftendesirable that a sensor 42 should have a substrate 50 which isnon-toxic. Substrate 50 may be one that is approved by one or moreappropriate governmental agencies or private groups for in vivo use.Although substrate 50 in at least some embodiments has uniformdimensions along the entire length of the sensor, in other embodimentssubstrate 50 has a distal end 67 and a proximal end 65 with differentwidths 53, 55, respectively, as illustrated for example in FIG. 13.

At least one conductive trace 52 may be formed on the substrate for usein constructing a working electrode 58. In addition, other conductivetraces 52 may be formed on the substrate 50 for use as electrodes (e.g.,additional working electrodes, as well as counter, counter/reference,and/or reference electrodes) and other components, such as a temperatureprobe. The conductive traces 52 may extend most of the distance along alength 57 of the sensor 42, as illustrated for example in FIG. 13,although this is not necessary. The placement of the conductive traces52 may depend on the particular configuration of the analyte monitoringsystem (e.g., the placement of control unit contacts and/or the samplechamber in relation to the sensor 42). For implantable sensors,particularly subcutaneously implantable sensors, the conductive tracesmay extend close to the tip of the sensor 42 to minimize the amount ofthe sensor that must be implanted.

The conductive traces may be formed using a conductive material 56 suchas carbon (e.g., graphite), a conductive polymer, a metal or alloy(e.g., gold or gold alloy), or a metallic compound (e.g., rutheniumdioxide or titanium dioxide), and the like. Conductive traces 52 (andchannels 54, if used) may be formed with relatively narrow widths. Inembodiments with two or more conductive traces 52 on the same side ofthe substrate 50, the conductive traces 52 are separated by distancessufficient to prevent conduction between the conductive traces 52. Theworking electrode 58 and the counter electrode 60 (if a separatereference electrode is used) may be made using a conductive material 56,such as carbon.

Reference electrode 62 and/or counter/reference electrode may be formedusing conductive material 56 that is a suitable reference material, forexample silver/silver chloride or a non-leachable redox couple bound toa conductive material, for example, a carbon-bound redox couple.

The electrical contact 49 may be made using the same material as theconductive material 56 of conductive traces 52 or alternatively, may bemade from a carbon or other non-metallic material, such as a conductingpolymer.

A number of exemplary electrode configurations are described herein,however, it will be understood that other configurations may also beused. In certain embodiments, e.g., illustrated in FIG. 14A, the sensor42 includes two working electrodes 58 a, 58 b and one counter electrode60, which also functions as a reference electrode. In anotherembodiment, the sensor includes one working electrode 58 a, one counterelectrode 60, and one reference electrode 62, as shown for example inFIG. 14B. Each of these embodiments is illustrated with all of theelectrodes formed on the same side of the substrate 50.

Alternatively, one or more of the electrodes may be formed on anopposing side of the substrate 50. In another embodiment, two workingelectrodes 58 and one counter electrode 60 are formed on one side of thesubstrate 50 and one reference electrode 62 and two temperature probes66 are formed on an opposing side of the substrate 50, as illustrated inFIG. 16. The opposing sides of the tip of this embodiment of the sensor42 are illustrated in FIGS. 17 and 18.

Some analytes, such as oxygen, may be directly electrooxidized orelectroreduced on the working electrode 58. Other analytes, such asglucose and lactate, require the presence of at least one electrontransfer agent and/or at least one catalyst to facilitate theelectrooxidation or electroreduction of the analyte. Catalysts may alsobe used for those analytes, such as oxygen, that can be directlyelectrooxidized or electroreduced on the working electrode 58. For theseanalytes, each working electrode 58 has a sensing layer 64 formedproximate to or on a working surface of the working electrode 58. Inmany embodiments, the sensing layer 64 is formed near or on only a smallportion of the working electrode 58, e.g., near a tip of sensor 42.

The sensing layer 64 includes one or more components designed tofacilitate the electrolysis of the analyte. Sensing layer 64 may beformed as a solid composition of the desired components (e.g., anelectron transfer agent and/or a catalyst). These components may benon-leachable from the sensor 42 and may be immobilized on the sensor42. For example, the components may be immobilized on a workingelectrode 58. Alternatively, the components of the sensing layer 64 maybe immobilized within or between one or more membranes or films disposedover the working electrode 58 or the components may be immobilized in apolymeric or sol-gel matrix. Examples of immobilized sensing layers aredescribed in, e.g., U.S. Pat. Nos. 5,262,035; 5,264,104; 5,264,105;5,320,725; 5,593,852; and 5,665,222; and PCT Patent Application No.US1998/002403 entitled “Electrochemical Analyte Sensors UsingThermostable Soybean Peroxidase”, filed on Feb. 11, 1998, published asWO-1998/035053.

Sensors having multiple working electrodes 58 a may also be used, e.g.,and the signals therefrom may be averaged or measurements generated atthese working electrodes 58 a may be averaged. In addition, multiplereadings at a single working electrode 58 a or at multiple workingelectrodes may be averaged.

In many embodiments, sensing layer 64 contains one or more electrontransfer agents in contact with the conductive material 56 of workingelectrode 58, as shown for example in FIGS. 14A and 14B. Useful electrontransfer agents and methods for producing them are described in, e.g.,U.S. Pat. Nos. 5,264,104; 5,356,786; 5,262,035; 5,320,725; 6,175,752;6,329,161; and elsewhere. The sensing layer 64 may also include acatalyst which is capable of catalyzing a reaction of the analyte. Thecatalyst may also, in some embodiments, act as an electron transferagent.

To electrolyze the analyte, a potential (versus a reference potential)is applied across the working and counter electrodes 58, 60. When apotential is applied between the working electrode 58 and the counterelectrode 60, an electrical current will flow. Those skilled in the artwill recognize that there are many different reactions that will achievethe same result; namely the electrolysis of an analyte or a compoundwhose level depends on the level of the analyte.

A variety of optional items may be included in a sensor. One optionalitem is a temperature probe 66 (see for example FIG. 18). One exemplarytemperature probe 66 is formed using two probe leads 68, 70 connected toeach other through a temperature-dependent element 72 that is formedusing a material with a temperature-dependent characteristic. An exampleof a suitable temperature-dependent characteristic is the resistance ofthe temperature-dependent element 72. The temperature probe 66 canprovide a temperature adjustment for the output from the workingelectrode 58 to offset the temperature dependence of the workingelectrode 58.

The sensors of the subject invention are biocompatible. Biocompatibilitymay be achieved in a number of different manners. For example, anoptional biocompatible layer 73 may be formed over at least that portionof the sensor 42 which is inserted into the patient, as shown in FIG.19.

An interferant-eliminating layer (not shown) may be included in thesensor 42. The interferant-eliminating layer may include ioniccomponents, such as Nafion® or the like, incorporated into a polymericmatrix to reduce the permeability of the interferant-eliminating layerto ionic interferants having the same charge as the ionic components.

A mass transport limiting layer 71 may be included with the sensor toact as a diffusion-limiting barrier to reduce the rate of mass transportof the analyte, for example, glucose or lactate, into the region aroundthe working electrodes 58. Exemplary layers that may be used aredescribed for example, in U.S. Pat. No. 6,881,551, and elsewhere.

A sensor of the subject invention may be adapted to be a replaceablecomponent in an in vivo analyte monitor, and particularly in animplantable analyte monitor. As described above, in many embodiments thesensor is capable of operation over a period of days or more, e.g., aperiod of operation may be at least about one day, e.g., at least aboutthree days, e.g., at least about five days, e.g., at least about oneweek or more, e.g., one month or more. The sensor may then be removedand replaced with a new sensor.

The various embodiments of the present invention may also be employed tomaintain a therapeutic agent delivery system on-body, e.g., an infusiondevice and/or infusion sets. Embodiments includes analyte monitoringsystems used in sensor-based therapeutic agent (e.g., insulin) deliverysystems, wherein the subject invention is included to secure one or morecomponents thereof on a body part of a patient.

The system may provide a therapeutic agent to counteract the high or lowlevel of an analyte in response to the signals from one or more sensors.Alternatively, the system may monitor the drug concentration to ensurethat the drug remains within a desired therapeutic range. The system mayinclude one or more (e.g., two or more) sensors, an on-skin sensorcontrol unit and one or more on-body securement elements, areceiver/display unit, a data storage and controller module, and a drugadministration system. In some cases, the receiver/display unit, datastorage and controller module, and drug administration system may beintegrated in a single unit. The sensor-based therapeutic agent deliverysystem may use data from the one or more sensors to provide necessaryinput for a control algorithm/mechanism in the data storage andcontroller module to adjust the administration of therapeutic agent. Asan example, a glucose sensor may be used to control and adjust theadministration of insulin.

Finally, kits for use in practicing the various embodiments of thesubject invention are also provided. The subject kits may include one ormore on-body securement elements as described herein. Embodiments mayalso include a sensor and/or a sensor control unit.

In addition to one or more of the above-described components, thesubject kits may also include written instructions for using a sensorand/or on-body securement elements. The instructions may be printed on asubstrate, such as paper or plastic, etc. As such, the instructions maybe present in the kits as a package insert, in the labeling of thecontainer of the kit or components thereof (i.e., associated with thepackaging or sub-packaging) etc. In other embodiments, the instructionsare present as an electronic storage data file present on a suitablecomputer readable storage medium, e.g., CD-ROM, diskette, etc. In yetother embodiments, the actual instructions are not present in the kit,but means for obtaining the instructions from a remote source, e.g., viathe Internet, are provided. An example of this embodiment is a kit thatincludes a web address where the instructions can be viewed and/or fromwhich the instructions can be downloaded. As with the instructions, thismeans for obtaining the instructions is recorded on a suitablesubstrate.

In many embodiments of the subject kits, the components of the kit arepackaged in a kit containment element to make a single, easily handledunit, where the kit containment element, e.g., box or analogousstructure, may or may not be an airtight container, e.g., to furtherpreserve the one or more sensors and additional reagents (e.g., controlsolutions), if present, until use.

In accordance with one embodiment of the present invention, mountingunits with adhesive skin patches mated with control units and positionedon body surfaces (such as arm or abdomen) may be used in conjunctionwith second on-body securement elements retained substantially in itsoriginal position on the body surface for approximately 110 hourswithout substantial dislodgment. In the aforementioned embodiment,second on-body securement elements in the form of overbandages may beused. The overbandages include a casting layer, backing film, adhesiveand release liner system, for example, as shown in to FIG. 12A, where acentral through-hole is provided and sized to accommodate the controlunit with a small clearance to facilitate application.

The overbandages may be designed to adhere only to the extended ring ofthe skin patch of the mounting unit and to provide increased adhesivearea for skin adhesion. In this manner, the control units remaineduncovered by the overbandages, reducing the likelihood of leavingadhesive residue on the control units. Moreover, this embodimentprovides easier applications (with one hand and without line-of-sight)as compared to the other bandages. This may be achieved by the controlunits serving as lead-ins for positioning the overbandages, the tabsthereof exposing the “tack-in-place” spot of adhesive, and the easilyremovable release liner peel features.

In this manner, in one embodiment of the present invention, easyapplication and/or removal of overbandages for securing medical devicessuch as, for example, analyte sensor in combination with on-bodysecurement elements is provided. Moreover, in accordance with thevarious embodiments of the present invention, there are provided devicesand methods for maintaining a medical device on-body that provides,among others, ease of use, even in instances in which the medical deviceis to be maintained on a body part that is not within the direct line ofsite of the patient, and comfort. Furthermore, the subject invention invarious embodiments provides a patient with a high degree of confidencethat the medical device is securely maintained in position on a bodypart.

While the present invention has been described with reference to thespecific embodiments thereof, it should be understood by those skilledin the art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of theinvention. In addition, many modifications may be made to adapt aparticular situation, material, composition of matter, process, processstep or steps, to the objective, spirit and scope of the presentinvention. All such modifications are intended to be within the scope ofthe claims appended hereto.

What is claimed is:
 1. A device, comprising: a non-adhesive backinghaving a first surface and a second surface; and an adhesive disposed onat least a portion of the first surface of the non-adhesive backingforming an adhesive portion and a non-adhesive portion on the firstsurface of the non-adhesive backing, the non-adhesive portionpositionable over a medical device and sized and configured so that themedical device is not contacted with the adhesive portion when thenon-adhesive portion is positioned over the medical device, thenon-adhesive portion including an opening, and a transparent shieldcovering the opening.
 2. The device of claim 1, further including aremovable release liner adjacent the adhesive.
 3. The device of claim 1,further including a removable casting layer adjacent the second surfaceof the non-adhesive backing.
 4. The device of claim 1, wherein theadhesive portion is opaque.
 5. The device of claim 1, wherein thenon-adhesive portion comprises a pouch.
 6. The device of claim 1,wherein the adhesive portion is configured for adherence to an adhesivepatch on which the medical device is positioned.
 7. The device of claim1, wherein the medical device includes one of sensor electronics, an RFreceiver unit, a data monitoring device, an infusion device, or a remotecontrol unit.
 8. A system, comprising: sensor electronics having ahousing and a sensor extending from the housing, the housing including asurface covered with an adhesive to adhere to a skin surface; and adevice configured to be positionable over at least a portion of thehousing, wherein the device comprises: a non-adhesive backing having afirst surface and a second surface; and an adhesive disposed on at leasta portion of the first surface of the non-adhesive backing forming anadhesive portion and a non-adhesive portion on the first surface of thenon-adhesive backing, the non-adhesive portion positionable over amedical device and sized and configured so that the medical device isnot contacted with the adhesive portion when the non-adhesive portion ispositioned over the medical device, the non-adhesive portion includingan opening, and a transparent shield covering the opening.
 9. The systemof claim 8, wherein the adhesive and the housing are water resistant orwaterproof.
 10. The system of claim 8, further including a removablerelease liner adjacent the adhesive.
 11. The system of claim 10, whereinthe removable release liner comprises a plurality of removable releaseliners adjacent the adhesive covered surface.
 12. The system of claim 8,further including a removable casting layer adjacent the second surfaceof the non-adhesive backing.
 13. The system of claim 8, wherein thetransparent shield is configured to be positioned over the sensorelectronics.
 14. The system of claim 8, wherein the transparent shieldis compressible.